Added commentary about ContentRegion functions. Added internal GetContentRegionMaxScreen() to facilitate internal code at the moment.

imgui.cpp

@@ -2978,9 +2978,9 @@ float ImGui::CalcWrapWidthForPos(const ImVec2& pos, float wrap_pos_x)
     if (wrap_pos_x < 0.0f)
         return 0.0f;
 
-    ImGuiWindow* window = GetCurrentWindowRead();
+    ImGuiWindow* window = GImGui->CurrentWindow;
     if (wrap_pos_x == 0.0f)
-        wrap_pos_x = GetContentRegionMax().x + window->Pos.x;
+        wrap_pos_x = GetContentRegionMaxScreen().x;
     else if (wrap_pos_x > 0.0f)
         wrap_pos_x += window->Pos.x - window->Scroll.x; // wrap_pos_x is provided is window local space
 
@@ -5775,7 +5775,7 @@ void ImGui::PopItemWidth()
 // Calculate default item width given value passed to PushItemWidth()
 float ImGui::CalcItemWidth()
 {
-    ImGuiWindow* window = GetCurrentWindowRead();
+    ImGuiWindow* window = GImGui->CurrentWindow;
     float w = window->DC.ItemWidth;
     if (w < 0.0f)
     {
@@ -5791,10 +5791,10 @@ float ImGui::CalcItemWidth()
 // Note that only CalcItemWidth() is publicly exposed.
 ImVec2 ImGui::CalcItemSize(ImVec2 size, float default_w, float default_h)
 {
-    ImGuiWindow* window = GetCurrentWindowRead();
+    ImGuiWindow* window = GImGui->CurrentWindow;
     ImVec2 content_max;
     if (size.x < 0.0f || size.y < 0.0f)
-        content_max = window->Pos + GetContentRegionMax();
+        content_max = GetContentRegionMaxScreen();
     if (size.x <= 0.0f)
         size.x = (size.x == 0.0f) ? default_w : ImMax(content_max.x - window->DC.CursorPos.x, 4.0f) + size.x;
     if (size.y <= 0.0f)
@@ -6367,17 +6367,27 @@ void ImGui::SetNextWindowBgAlpha(float alpha)
 // FIXME: This is in window space (not screen space!)
 ImVec2 ImGui::GetContentRegionMax()
 {
-    ImGuiWindow* window = GetCurrentWindowRead();
+    ImGuiWindow* window = GImGui->CurrentWindow;
     ImVec2 mx = window->ContentsRegionRect.Max - window->Pos;
     if (window->DC.CurrentColumns)
         mx.x = GetColumnOffset(window->DC.CurrentColumns->Current + 1) - window->WindowPadding.x;
     return mx;
 }
 
+// [Internal] Absolute coordinate. Saner. This is not exposed until we finishing refactoring work rect features.
+ImVec2 ImGui::GetContentRegionMaxScreen()
+{
+    ImGuiWindow* window = GImGui->CurrentWindow;
+    ImVec2 mx = window->ContentsRegionRect.Max;
+    if (window->DC.CurrentColumns)
+        mx.x = window->Pos.x + GetColumnOffset(window->DC.CurrentColumns->Current + 1) - window->WindowPadding.x;
+    return mx;
+}
+
 ImVec2 ImGui::GetContentRegionAvail()
 {
-    ImGuiWindow* window = GetCurrentWindowRead();
-    return GetContentRegionMax() - (window->DC.CursorPos - window->Pos);
+    ImGuiWindow* window = GImGui->CurrentWindow;
+    return GetContentRegionMaxScreen() - window->DC.CursorPos;
 }
 
 float ImGui::GetContentRegionAvailWidth()

imgui.h

@@ -261,18 +261,12 @@ namespace ImGui
     IMGUI_API bool          IsWindowFocused(ImGuiFocusedFlags flags=0); // is current window focused? or its root/child, depending on flags. see flags for options.
     IMGUI_API bool          IsWindowHovered(ImGuiHoveredFlags flags=0); // is current window hovered (and typically: not blocked by a popup/modal)? see flags for options. NB: If you are trying to check whether your mouse should be dispatched to imgui or to your app, you should use the 'io.WantCaptureMouse' boolean for that! Please read the FAQ!
     IMGUI_API ImDrawList*   GetWindowDrawList();                        // get draw list associated to the current window, to append your own drawing primitives
-
     IMGUI_API ImVec2        GetWindowPos();                             // get current window position in screen space (useful if you want to do your own drawing via the DrawList API)
     IMGUI_API ImVec2        GetWindowSize();                            // get current window size
     IMGUI_API float         GetWindowWidth();                           // get current window width (shortcut for GetWindowSize().x)
     IMGUI_API float         GetWindowHeight();                          // get current window height (shortcut for GetWindowSize().y)
-    IMGUI_API ImVec2        GetContentRegionMax();                      // current content boundaries (typically window boundaries including scrolling, or current column boundaries), in windows coordinates
-    IMGUI_API ImVec2        GetContentRegionAvail();                    // == GetContentRegionMax() - GetCursorPos()
-    IMGUI_API float         GetContentRegionAvailWidth();               // == GetContentRegionAvail().x
-    IMGUI_API ImVec2        GetWindowContentRegionMin();                // content boundaries min (roughly (0,0)-Scroll), in window coordinates
-    IMGUI_API ImVec2        GetWindowContentRegionMax();                // content boundaries max (roughly (0,0)+Size-Scroll) where Size can be override with SetNextWindowContentSize(), in window coordinates
-    IMGUI_API float         GetWindowContentRegionWidth();              //
 
+    // Prefer using SetNextXXX functions (before Begin) rather that SetXXX functions (after Begin).
     IMGUI_API void          SetNextWindowPos(const ImVec2& pos, ImGuiCond cond = 0, const ImVec2& pivot = ImVec2(0,0)); // set next window position. call before Begin(). use pivot=(0.5f,0.5f) to center on given point, etc.
     IMGUI_API void          SetNextWindowSize(const ImVec2& size, ImGuiCond cond = 0);                  // set next window size. set axis to 0.0f to force an auto-fit on this axis. call before Begin()
     IMGUI_API void          SetNextWindowSizeConstraints(const ImVec2& size_min, const ImVec2& size_max, ImGuiSizeCallback custom_callback = NULL, void* custom_callback_data = NULL); // set next window size limits. use -1,-1 on either X/Y axis to preserve the current size. Use callback to apply non-trivial programmatic constraints.
@@ -290,6 +284,15 @@ namespace ImGui
     IMGUI_API void          SetWindowCollapsed(const char* name, bool collapsed, ImGuiCond cond = 0);   // set named window collapsed state
     IMGUI_API void          SetWindowFocus(const char* name);                                           // set named window to be focused / front-most. use NULL to remove focus.
 
+    // Content region
+    // - Those functions are bound to be redesigned soon (they are confusing, incomplete and return values in local window coordinates which increases confusion)
+    IMGUI_API ImVec2        GetContentRegionMax();                                          // current content boundaries (typically window boundaries including scrolling, or current column boundaries), in windows coordinates
+    IMGUI_API ImVec2        GetContentRegionAvail();                                        // == GetContentRegionMax() - GetCursorPos()
+    IMGUI_API float         GetContentRegionAvailWidth();                                   // == GetContentRegionAvail().x
+    IMGUI_API ImVec2        GetWindowContentRegionMin();                                    // content boundaries min (roughly (0,0)-Scroll), in window coordinates
+    IMGUI_API ImVec2        GetWindowContentRegionMax();                                    // content boundaries max (roughly (0,0)+Size-Scroll) where Size can be override with SetNextWindowContentSize(), in window coordinates
+    IMGUI_API float         GetWindowContentRegionWidth();                                  //
+
     // Windows Scrolling
     IMGUI_API float         GetScrollX();                                                   // get scrolling amount [0..GetScrollMaxX()]
     IMGUI_API float         GetScrollY();                                                   // get scrolling amount [0..GetScrollMaxY()]

imgui_internal.h

@@ -1444,6 +1444,7 @@ namespace ImGui
     IMGUI_API void          PushItemFlag(ImGuiItemFlags option, bool enabled);
     IMGUI_API void          PopItemFlag();
     IMGUI_API bool          IsItemToggledSelection();                                           // was the last item selection toggled? (after Selectable(), TreeNode() etc. We only returns toggle _event_ in order to handle clipping correctly)
+    IMGUI_API ImVec2        GetContentRegionMaxScreen();
 
     // Logging/Capture
     IMGUI_API void          LogBegin(ImGuiLogType type, int auto_open_depth);   // -> BeginCapture() when we design v2 api, for now stay under the radar by using the old name.

imgui_widgets.cpp

@@ -5057,7 +5057,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
     // We vertically grow up to current line height up the typical widget height.
     const float text_base_offset_y = ImMax(padding.y, window->DC.CurrentLineTextBaseOffset); // Latch before ItemSize changes it
     const float frame_height = ImMax(ImMin(window->DC.CurrentLineSize.y, g.FontSize + style.FramePadding.y*2), label_size.y + padding.y*2);
-    ImRect frame_bb = ImRect(window->DC.CursorPos, ImVec2(window->Pos.x + GetContentRegionMax().x, window->DC.CursorPos.y + frame_height));
+    ImRect frame_bb = ImRect(window->DC.CursorPos, ImVec2(GetContentRegionMaxScreen().x, window->DC.CursorPos.y + frame_height));
     if (display_frame)
     {
         // Framed header expand a little outside the default padding